The Australian one ounce silver piece (abbreviated as 1 oz and designated with Ag for "silver") is a bullion and commemorative coin format. Uniquely, in Australia there are two mints authorised to strike legal tender: the Royal Australian Mint (which also makes the country's circulating coinage) and the Perth Mint which only makes collector and bullion coins, as well as other bullion products.
The Australian Silver Kookaburra series was introduced in 1990 by the Perth Mint; subsequently, the Royal Australian Mint also started issuing silver Kookaburra bullion coins. The coins have legal tender status in Australia and are one of very few legal tender bullion silver coins to change their design every year, always featuring a kookaburra - a bird native to Australia. This and their limited annual mintage may, unlike for many other bullion coins, raise their numismatic value over the value of silver used.
The overall weight is slightly more than a troy ounce so that the coins have exactly 1.000 oz ASW (one ounce of Absolute Silver Weight). | 
